Direct current gas discharge Ion-Beam Sources with a Magnetic Layer (IBSML) and with an Anode Layer (IBSAL) are widely used in space and in an ion-beam processing technology: as thrusters in the space technology (IBSML), and as ion-beam sources in Protective Over-coats, In-situ Cleaning, Ion-assisted Deposition, Optical Coatings, Enhanced Sputtering, etc. in industrial ion beam processing technologies (IBSML, IBSAL).
These families of Ion-Beam Sources offer a simplicity in design and maintenance, increased reliability at a decreased maintenance cost, long life (theoretically an infinitesimally long life) with application of a commercially available power supply. The cross-section of an Ion-Beam Source with an Anode Layer is shown schematically in FIG. 3. It comprises a planar long anode 1 of a conductive non-magnetic material mounted on a magnetoconductor 2 of low-carbon steel by insulators 5, two long magnetoconductive poles 3, and a continuation of the magnetoconductor 2 positioned symmetrically above and along the anode 1 with a permanent discharge gap between the anode surface and the poles and with a permanent magnetic gap between the mentioned poles, and a permanent magnet 4 positioned between the pole 3 and the magnetoconductor associated with the pole 2.
The operating voltage is applied between the anode 1 and the poles 2, 3 used as a cathodes and grounded in standard applications. The Ion-Beam Source with the cross-section shown in FIG. 3 could be formed of any length. However, both the ends of this Ion-Beam Source should be connected to one another in order to have an uninterrupted closed magnetic gap above an uninterrupted closed anode surface under uninterrupted surfaces of the magnetic poles. This requirement of the closeness of the Ion-Beam Source elements is a consequence of the condition of a closeness of an electron drift in the crossed electrical E and magnetic H fields formed by the surface of the anode 1 together with the surfaces of the poles 2 and 3 serving as the cathodes. Indeed, if one were to form the crossed electrical E and magnetic H fields in accordance with the configuration of the electrodes and poles shown in FIG. 3(a), one can expect the drift of the electrons as it shown in FIG. 2, i. e. along the magnetic gap shown in FIG. 3, because in practice, the presence of the second electrode (cathode) shown in FIG. 3(a) is not necessary if one uses the magnetic poles as the cathode, due to the electric potential of the magnetic poles connection to one another by plasma, see FIG. 3(b).
For a plasma ignition and for a maintenance of plasma uniformity into the magnetic (and electrical) gap, the requirements for the closeness of the electron drift and the requirements for the closeness of the magnetic and the electrical gaps must consequently be followed. These requirements create a certain obvious inconvenience in design and application of the Ion-Beam Sources with an Anode Layer. The second problem is the requirement for applying the magnetoconductor (2 in FIG. 3) as the necessary element of the IBSAL. It is understood that the magnetoconductor significantly increases the weight of the IBSAL and therefore makes it impossible to consider it for space technology, and being fabricated entirely of a low-carbon steel (desirable design), it has high fabrication cost.
The present invention enables one to overcome all these considered problems by replacing the magnetic poles including the magnetoconductor in IBSAL with a corresponding quadrupole magnetic system.